304 research outputs found
Solitons and excitations in the duality-based matrix model
We analyse a specific, duality-based generalization of the hermitean matrix
model. The existence of two collective fields enables us to describe specific
excitations of the hermitean matrix model. By using these two fields, we
construct topologically non-trivial solutions (BPS solitons) of the model. We
find the low-energy spectrum of quantum fluctuations around the uniform
solution. Furthermore, we construct the wave functional of the ground state and
obtain the corresponding Green function.Comment: 13 pages,v2: new solutions constructed, title changed accordingl
Comment on "Solitons and excitations in the duality-based matrix model"
It is shown that a method for constructing exact multi-solitonic solutions of
the coupled BPS equations in the duality-based generalization of the hermitean
matrix model, which was put forward in a recent paper, is not correct.Comment: 5 pages, no figures, JHEP-style, submitted to JHE
Solitons in the Calogero model for distinguishable particles
We consider a large two-family Calogero model in the Hamiltonian,
collective-field approach. The Bogomol'nyi limit appears and the corresponding
solutions are given by the static-soliton configurations. Solitons from
different families are localized at the same place. They behave like a paired
hole and lump on the top of the uniform vacuum condensates, depending on the
values of the coupling strengths. When the number of particles in the first
family is much larger than that of the second family, the hole solution goes to
the vortex profile already found in the one-family Calogero model.Comment: 14 pages, no figures, late
Susceptibility of red flour beetle Tribolium castaneum (Herbst) populations from Serbia to contact insecticides
Contact insecticides remain the principal option for controlling stored-product insects. Unsatisfactory results of insecticide applications are caused by several factors, one of the most important being resistance of stored-product insects. The objective of this study was to examine the susceptibility in several populations of red flour beetle Tribolium castaneum (Herbst) from Serbia to different contact insecticides. Toxicity of the insecticides dichlorvos, malathion, chlorpyrifos-methyl, pirimiphos-methyl, deltamethrin and bifenthrin to adults of a laboratory population of T. castaneum was investigated in the laboratory by topical application. At the LD50, deltamethrin was the most toxic and malathion the least toxic of the insecticides. Discriminating dose data for the laboratory population were used to test the susceptibility of 10 other populations originating from different storage facilities (silos, warehouses and flour mills) in Serbia. The discriminating dose of malathion caused mortality of up to 85% in seven populations, indicating malathion resistance in those populations. For two populations of T. castaneum from Nikinci and Jakovo LD values, ld-p lines and levels of susceptibility/resistance (RRs) were determined. The most toxic insecticide for adults from Nikinci and Jakovo was deltamethrin, while malathion was least toxic. The resistance ratios (RRs) for malathion at the LD50 were 17.6 for beetles from Nikinci, and 26.0 for beetles from Jakovo. Keywords: Tribolium castaneum adults; Different populations; Insecticide toxicity; Susceptibility resistanc
A Nonrelativistic Chiral Soliton in One Dimension
I analyze the one-dimensional, cubic Schr\"odinger equation, with
nonlinearity constructed from the current density, rather than, as is usual,
from the charge density. A soliton solution is found, where the soliton moves
only in one direction. Relation to higher-dimensional Chern--Simons theory is
indicated. The theory is quantized and results for the two-body quantum problem
agree at weak coupling with those coming from a semiclassical quantization of
the soliton.Comment: 11 pages, Latex2
Radijaciono higijenska kontrola mineralnih dodataka i smeša za ishranu svinja
Radiometric control of products involved in the food chain is an important part of ongoing quality control of products related to food and feed. Content of primordial and anthropogenic radionuclides in some products directly determines their quality and further methods of usage. The most common way of intake of radionuclides in the human body is ingestion (80 %) through contaminated food and water. The foods of animal origin are largely represented in the human diet. Therefore radiation control of animal feeds and animal products will contribute to producing food for human nutrition without or with low risk for health. This paper presents the results obtained by gamma spectrometric analysis of mineral additives and mixtures for pig nutrition, from imported and domestic production. In most samples examined, activity levels of natural and radionuclides made during production were in accordance with the regulations. A certain number of tested mineral supplement samples had increased levels of activity of 238U (640- 2100 Bq/kg), which was not in accordance with applicable regulations.Radiometrijska kontrola proizvoda uključenih u lanac ishrane je važan segment stalne provere kvaliteta proizvoda vezanih za ishranu ljudi i životinja. Sadržaj primordijalnih i antropogenih radionuklida u nekim proizvodima direktno određuje njegov kvalitet i dalji način upotrebe. Najčešći put unošenja radionuklida u ljudski organizam je ingestija (80%), putem kontaminirane hrane i vode. Kako su namirnice životinjskog porekla zastupljene u velikoj količini u ishrani ljudi, kontrola hrane za životinje i proizvoda animalnog porekla omogućila bi ishranu ljudima bez rizika. U radu su prikazani rezultati dobijeni gamaspektrometrijskom analizom mineralnih dodataka, pred smeša i gotovih smeša za ishranu svinja iz uvoza i domaće proizvodnje. U većini ispitivanih uzoraka nivo aktivnosti prirodnih i proizvedenih radionuklida je bio u skladu sa propisima. Jedan broj ispitanih uzoraka mineralnih dodataka iz uvoza i domaće proizvodnje imao je povećan nivo aktivnost 238U (640 - 2100 Bq/kg), što nije u skladu sa važećim propisima
Quantum fluctuations of the Chern-Simons theory and dynamical dimensional reduction
We consider a large-N Chern-Simons theory for the attractive bosonic matter
(Jackiw-Pi model) in the Hamiltonian collective-field approach based on the 1/N
expansion. We show that the dynamics of low-lying density excitations around
the ground-state vortex configuration is equivalent to that of the Sutherland
model. The relationship between the Chern-Simons coupling constant lambda and
the Calogero-Sutherland statistical parameter lambda_s signalizes some sort of
statistical transmutation accompanying the dimensional reduction of the initial
problem.Comment: 10 pages, 2 figure
Solitons and giants in matrix models
We present a method for solving BPS equations obtained in the
collective-field approach to matrix models. The method enables us to find BPS
solutions and quantum excitations around these solutions in the one-matrix
model, and in general for the Calogero model. These semiclassical solutions
correspond to giant gravitons described by matrix models obtained in the
framework of AdS/CFT correspondence. The two-field model, associated with two
types of giant gravitons, is investigated. In this duality-based matrix model
we find the finite form of the -soliton solution. The singular limit of this
solution is examined and a realization of open-closed string duality is
proposed.Comment: 17 pages, JHEP cls; v2: final version to appear in JHEP, 2 references
added, physical motivation and interpretation clarifie
Totally classical Calogero model
We show that the standard Calogero Lax matrix can be interpreted as a
function on the fuzzy sphere and the Avan-Talon r-matrix as a function on the
direct product of two fuzzy spheres. We calculate the limiting Lax function and
r-function when the fuzzy sphere tends to the ordinary sphere and we show that
they define an integrable model interpreted as a large N Calogero model by
Bordemann, Hoppe and Theisen.Comment: 13 pages, revised version taking into account relevant results by
Bordemann, Hoppe and Theise
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